BirdAnalyst
Species · Minnesota · BBS 2025 Release · 1966–2024

Brewer's Blackbird Population Trend in Minnesota

All statesGeneralists

Brewer's Blackbird in Minnesota has fallen sharply: down 69% on the route-weighted index since 1969.

-69%Since 1969TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
72Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Brewer's Blackbird Trends in MinnesotaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Brewer's Blackbird has fallen sharply in Minnesota: down 69% on the route-weighted index since 1969.

Brewer's Blackbird Population Forecast in Minnesota

If the recent trend holds, Brewer's Blackbird in Minnesota is projected to fall about 33% by 2029 — from 2.1 in 2024 to a central estimate of 1.4 (95% range 0.00–5.4). A 5-year backtest shows a typical error of ±13.4%, with 100% of held-out values landing inside the 95% band.

-33%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
1.4Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–5.495% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±13.4%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Brewer's Blackbird in Minnesota is projected to fall about 33% by 2029 — from 2.1 in 2024 to a central estimate of 1.4 (95% range 0.00–5.4). A 5-year backtest shows a typical error of ±13.4%, with 100% of held-out values landing inside the 95% band.19672029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20251.80.005.7
20261.70.005.7
20271.60.005.6
20281.50.005.5
20291.40.005.4

Brewer's Blackbird Survey Routes in Minnesota

Routes recording Brewer's Blackbird in Minnesota.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Lockhart3820241993
Oklee2520211979
Bemidji2419791979
Ash Creek2019851985
Lake Bronson2020111978
Beltrami1320241967
Greenbush1220241994
Courtland1020241978
Maynard1020131968
Badger920181978
Nebish920231985
Minnetonka819961969
Osseo820171968
Evergreen820241967
Money Creek719981998
Glyndon720241978
Debs720131970
Grygla720171976
Ashby720212006
Wigwam Bay619951967
Waskish619971980
Tamarac Nwr619921992
Huntley520241967
Knapp520021967
Pine River520241967

Brewer's Blackbird Population Trend in Other States

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Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.